Definition

Causes of Skin Lumps

Insect Bites. The most common cause of an itchy bump is a mosquito bite. Other insects can also cause little bumps.

Stings. A bee sting can cause a painful bump. The swelling can become quite large.

Lymph Nodes. Most common cause of a lump or mass felt under the skin. Commonly found in the neck or groin. Nodes have a boundary or edge and are movable. This is not the case for the swelling seen with insect bites. Lymph nodes become larger with infections.

Scalp Hematoma. The most common cause of a lump on the head is a scalp hematoma (goose egg). In a child under 2 years of age the injury may not have been seen.

Injuries. New lumps anywhere can be caused by an injury that wasn't observed. A bruise is often present with the swelling.

Callus. Broken bones heal with new bone formation. The medical term is callus. The callus feels like a bony knot that is larger than the bone itself. A callus is most commonly felt after a collarbone fracture.

Boils. A boil is a skin abscess. It causes a very painful red lump.

Lumps that are a Normal Part of the Body

Breast Bud. A small disc-shaped lump felt under the nipple. It indicates the onset of puberty in 7-12 year old girls.

External Occipital Protuberance. The bony lump felt at the base of the skull in back.

Mastoid Process. The bony lump felt behind each lower ear.

Xiphoid Process. A small hard lump felt at the lower end of the sternum (breastbone).